The invention relates to a hydraulic or pneumatic actuated holder along a holder beam for a rotating pressure blade cooperating with a hardened counter pressure roller. The invention is used for longitudinal separation of bands, especially from heavy materials, in a roll cutting machine, whereby the piston of a pressure housing is directly connected with a fork-shaped carrier of the pressure blade. The pressure housing has the shape of a flat can and is arranged in such a way that it is positioned with its narrow side parallel to the pressure blade axis and fastened flush on the open top side of a flat, nearly rectangular-shaped guide piece for the cutter carrier. The guide piece consists of two plates bolted against spacers.
A blade holder such as that which is described above is shown in British Pat. No. 14 70 357. It has the advantage of a small axial dimension, which determines the smallest possible width of the material strip to be cut between the neighboring cutter carriers.
Since nearly the whole cross-section of the narrow side of the rectangular shaped guide piece is utilized as a cylinder for a working piston, the known cutter carrier may exert considerable start-up force to the cutter in spite of its advantageous flat design. This force is necessary because the material is not cut by the blade but squeezed apart on a glass-hard counter pressure roller. Against this squeeze force, the blade is supported with its hub over a large area partially on the inside of the plates of the guide piece, and partially on the flush inside of the arms of the flat fork-shaped blade carrier and where the blade carrier also is supported within flat-vertical guide grooves of the plates in the axial direction. In spite of the advantageous flat design of the known blade carrier, the pressure blade can be pressed with strong force onto the glass-hard surface of the counter pressure roller and supported against tilt, so that the cutting edge of the blade may not be displaced axially on the counter roller. Such displacements would damage the machine and the material to be cut as it runs through. The pressure blade can be easily pulled out of the blade holder when it is in the lifted state relative to the counter pressure roller, and may be exchanged without dismantelling for the purpose of repair. In the known blade holders, the corners of the two plates, which are positioned opposite each other diagonal to the upper holder beam, have step-like cut-outs. The plates form a pair of flat guide grooves, positioned opposite each other for the flat-shaped fork-like cutter carrier from which extend branches into the sloped areas. The ends of the flat fork-shaped carrier of the squeeze blade form cut-outs against the open slide-in slots for the axle bolt of the pressure blade similar to that shown in U.S. Pat. No. 3,777,607.
The step-like cut-outs of the above described plate corners make it possible for the free positioned pressure blade to be pulled out forwardly and downwardly after it has been raised from the counter pressure roller. This also makes it possible to position in the open step area a felt strip and lubricator in the roller cut machine for the maintenance of the edges of the pressure blades.
However, these advantages on the known pressure blade holder have brought about some disadvantages, namely, that the mentioned step-shaped cut-outs within the plates reduce considerably the stiffness of the formed frame-shaped guide piece for the pressure blade and the fork-shaped pressure blade carrier. The result is an unclean squeeze cut in the material, especially when a tough or thick material has to be separated lengthwise into strips such as wrapping strips.
This invention suggests keeping the advantages of the known pressure blade holder, but to increase the stability of the parallel guide for the pressure blade in such a way that the step-shaped cut-outs, within the two plates are not used. Instead, slopes are formed whereby the plates on the upper ends of their slopes are stiffened by an additional bolting. This additional bolting is positioned with regard to the axle bolt of the extended pressure blade to the bolting on the lower holder beam connection nearly opposite.